Update: The site is fixed! Here’s what went wrong and who fixed it.
The website was down for about a day and a half, and I was getting concerned about it. I contacted the webmaster, Michael, and he contacted his nephew, Colin. Colin found the problem, which was a plug-in (a program within the website), that had gotten corrupted. The plug-in was disabled.
Thank you, Michael and Colin, for working to get this fixed! Now to do a prophecy update and get back on track.